Edwin medden



UNITED STATES PATENT CEETCE.

EDWIN MEDDEN, OF SENECA FALLS, NEW- YORK, ASSIGNOR TO THE SILSBY MANUFACTURING COMPANY, OF SAME PLACE.

ROTARY PU |v| P.

SPECIFICATION forming part of Letters Patent No. 237,764, dated February 15, 1881.

ApplicationfiledDecember 31,1880. (Model.)

To all whom it may concern:

Be it known that I, EDWIN MEDDEN, a citizen of the United States, residing at Seneca Falls, in the county of Seneca and State of New York, have invented Improvements in vRotary Pumps, of which the following is a specification.

In rotary pumps as heretofore constructed considerable difficulty has been experienced by reason ot' the unequal pressure in the suction and discharge chambers. The pressure in the suction-chamber is from the outside, or external, While the pressure in the dischargechamber is from the inside, or internal. The result of this is, that the sides of the case are forced apart, allowing a portion of the water to passback into the suction -chamber between the rotary pistons or cams and the case,

and also permitting Water to leakthrough theV stufng-boxes, thereby greatly compromising the efficiency of the pump. Y

To overcome this difficulty is the object of my invention; and it consists, iirst, in the provision of a stay-bolt applied, as hereinafter described, to the sides of the casing within the discharge-orifice.

The invention further consists in the combination, with the side plates ot' the casing, of a stay-bolt for securing them against spreading, and a sleeve surrounding the said bolt and forming a bearing on which the plates are securely clamped.

In order that the invention may be fully understood, I will proceed to describe it With reference to the accompanying drawings, in Which- Figure l is a transverse section ot a rotary pump illustrating the invention. Fig. 2 is a vertical longitudinal section of the same on the line 2 2, Fig. l, the plane of section passing through the sleeve and leaving the staybolt in elevation. Fig. 3 is a detached view of the bolt and sleeve.

H H are pistons or cams, of a form common in duplex rotary pumps, rotating in a casing, K, in the direction indicated by arrows, so as to take water through the induction-port F, and discharge it through the chamber A and one or more outlets, C C. The cam-shafts turn in stuffing-boxes, as usual.

The stay-bolt to which my inventionv particularly relates is shown at E, passing from side to side through the walls of the casing K at the delivery side thereof, and, by preference, as near as may be to the cams without interfering with their rotation. The bolt E passes through a sleeve, D. The object of the bolt E is to prevent the sides of the case K from spreading apart, and the sleeve D being made the proper length renders it impossible for any one to draw the sides of the case K too closely together when tightening the bolt E. The cause of the spreading apart of the upper parts of the sides of the case is the very great pressure attained in the dischargechamber ofthe pump,which sometimes reaches three hundred pounds to the square inch, and the result of the pressure from the outside ou the under parts of the sides of the case, which is considerably less than the pressure within the discharge-chamber and cannot exceed fifteen pounds to the square inch, renders it more possible for the upper parts of the sides ofthe case to spread apart.

This invention refers more particularly to rotary pumps as used for forcing water forextinguishing lires, especially on the portable steam lire-engine, but is applicable to rotary pumps in general.

Having thus described my invention, what I claim as new therein, and desire to secure by Letters Patent, is-

1. A rotary pump provided with a staybolt, E,passing through the plates K K of the casing, Within the discharge-chamber or delivery portion of said casing, substantially as herein shown and described.

2. The combination, in a rotary pump, of the casing-plates K K, stay-bolt E, and bearing-sleeve D, as and for the purposes set forth. y

EDWIN MEDDEN.

Witnesses:

R. DENNE, 01ans. W. RIEGEL. 

